Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Em que ano a escola da Universidade de Pittsburgh se juntou à liga de hóquei?
 ###Tabelas: CREATE TABLE cities_formerly_over_100000_people (cities_formerly_over_100000_people_id AUTO_INCREMENT PRIMARY KEY, City VARCHAR, State VARCHAR, 2010 population VARCHAR, Peak population (year) VARCHAR, Numeric decline from peak population VARCHAR, Percent decline from peak population VARCHAR) CREATE TABLE clausura_2004_standings (clausura_2004_standings_id AUTO_INCREMENT PRIMARY KEY, Place INT, Team VARCHAR, Played INT, Draw INT, Lost INT, Goals Scored INT, Goals Conceded INT, Points INT) CREATE TABLE list_of_oldest_sitting_mps_since_1945 (list_of_oldest_sitting_mps_since_1945_id AUTO_INCREMENT PRIMARY KEY, Born VARCHAR, Became oldest MP VARCHAR, Left House VARCHAR, Age on leaving VARCHAR, Died VARCHAR, Political Party VARCHAR) CREATE TABLE weekly_ratings (weekly_ratings_id AUTO_INCREMENT PRIMARY KEY, Episode VARCHAR, Air Date VARCHAR, Timeslot (EST) VARCHAR, Season INT, Rating INT, Share INT, 18–49 INT, Viewers (m) INT, Rank (#) VARCHAR) CREATE TABLE current_teams (current_teams_id AUTO_INCREMENT PRIMARY KEY, Institution VARCHAR, Location VARCHAR, Team Nickname VARCHAR, Joined TSCHL INT, Home Arena VARCHAR, Capacity INT, Team Website VARCHAR)  
SELECT Joined TSCHL FROM current_teams WHERE Institution = University of Pittsburgh